I've adjusted your point from the previous activity so it leaves a breadcrumb trail. This looks a lot like the breadcrumb trail from earlier in this chapter, but now it EXACTLY matches [code]f'(x)=2*x+2[/code], and isn't just close. Type [code]f'(x)=2x+2[/code] into the input bar again and see for yourself. Zoom way in to confirm that the breadcrumb trail is now an exact match.

Before we move on, I want to make a quick note about multiplication in Geogebra. Occasionally you might see me write[code] f'(x)=2x+2 [/code]or you might see me write [code]f'(x)=2*x+2.[/code] The difference of course is the "[code]*[/code]". [br][br]To be clear: both mean [i]exactly[/i] the same thing. Sometimes I put the "[code]*[/code]" in to make it clear that there is a multiplication in the definition of a function. However, as you know from your earlier studies, "[code]2x[/code]" always means "[code]2 times x[/code]", so technically, it's redundant. [br][br]Also, the good news is that Geogebra understands both, and interprets bot "[code]2x[/code]" and "[code]2*x[/code]" as [code][/code]2 times x, so feel free to use whichever you prefer. Usually, most people start out using "[code]2*x[/code]", but then later as they become more comfortable with the material, they get lazy, and drop the "[code]*[/code]". Whatever works for you is fine.[br][br]Move on when you're ready.